Fogged direct-positive silver halide emulsion containing as stabilizer a bisulfite addition product of an aldehyde

ABSTRACT

A DIRECT POSITIVE LIGHT-SENSITIVE SILVER HALIDE PHOTOGRAPHIC MATERIAL IS STABILIZED FOR STORAGE BY INCORPORATING THEREIN A POLYAMINE, A SALT OF A METAL MORE ELECTROPOSITIVE THAN SILVER AND A COMPOUND OF THE FORMULA   HO-(CH2)M-CH(-R)-SO3M   WHEREIN M IS 0 OR AN INTEGER OF 1 TO 8, R IS A HYDROGEN ATOM, OR AN ALKYL GROUP HAVING UP TO 17 CARBON ATOMS, OR AN ARYL GROUP AND M IS A CATION.

United States Patent 3,825,429 FOGGED DIRECT-POSITIVE SILVER HALIDEEMULSION CONTAINING AS STABILIZER A BISULFI'IE ADDITION PRODUCT OF ANALDEI-IYDE Tetsuo Furuya, Minami-Ashigara, Yoshio lbe and HideoKanisawa, Odawara, and Osakazu Sugino, Tokyo, Japan, assignors toKonishiroku Photo Industry Co., Ltd., Tokyo, Japan No Drawing. FiledDec. 6, 1972, Ser. No. 312,493 Int. Cl. G03c 1/28, N34 US. Cl. 96-108 5Claims ABSTRACT OF THE DISCLOSURE A direct positive light-sensitivesilver halide photographic material is stabilized for storage byincorporating therein a polyamine, a salt of a metal moreelectropositive than silver and a compound of the formula HOCH CH-SO3Mwherein m is 0 or an integer of 1 to 8, R is a hydrogen atom, or analkyl group having up to 17 carbon atoms, or an aryl group and M is acation.

This invention relates to a direct positive light-sensitive silverhalide photographic material having improved storability.

When a light-sensitive silver halide photographic material is exposed toa light and then developed, the density thereof increases withincreasing amount of exposure to reach the maximum value, in general.However, in case the amount of exposure is further increased, thedensity decreases again to finally form a positive image. Suchphenomenon is ordinarily called solarization. The solarizationphenomenon not only takes place due to excessive amount of exposure butalso is observed in the case where a silver halide emulsion, which haspreviously been fogged opically or chemically during the course ofpreparation thereof, is subjected to ordinary exposure. By utilizationof such phenomenon, therefore, it is possible to obtain a directpositive image. A light-sensitive silver halide photographic material,which has utilized the above-mentioned phenomenon, is generally called adirect positive silver halide photographic material, as is well known.

Ordinarily, a light-sensitive photographic material of this kind haspreviously been fogged chemically, and contains a silver halidephotographic emulsion which has been incorporated with a fogging agentprior to completion of second ripening of the emulsion. Typical examplesof the fogging agent used for the chemical fogging include aldehydecompounds such as formalin; sulfur compounds such as thiourea, thioureadioxide and thiosinamine; basic nitrogen-containing compounds such astriethylenetetramine, ethylenediamine and ammonia; inorganic reducingagents such as stannous chloride; and salts of metals moreelectropositive than silver such as chloroauric acid, palladous ammoniumchloride and platinic ammonium chloride.

However, direct positive light-sensitive silver halide photographicmaterials using the above-mentioned fogging agents have variousdisadvantages. For example, a silver halide emulsion fogged with thereducing agent is low in sensitivity, so that if the amount of light issmall, no reversal phenomenon can be attained, and the minimum densityis too high to provide the so-called clearness. On the other hand, if abasic nitrogen-containing compound is used as the fogging agent, theemulsion should be fogged at high pH and temperature. Accordingly, notonly the preparation of the emulsion becomes difiicult but also thefogged nuclei obtained become low in stability to make 3,825,429Patented July 23, 1974 the resulting photographic material unstable inphotographic properties. Further, in case a salt of a metal moreelectropositive than silver such as chloroauric acid is used, there isthe advantage that even a silver halide emulsion, which is relativelydifficulty fogged, can be easily fogged. On the other hand, however,there are such disadvantages that the fogged nuclei formed are toostrong to be destroyed by exposure and not only no substantialsolarization takes place but also the resulting image is extremely lowerin contrast.

Under such circumstances, many attempts have been made in order toovercome the abovernentioned disadvantages by use of various foggingagents in combination, but no satisfactory direct positivelight-sensitive silver halide photographic materials have yet beenobtained. Particularly the disadvantage of low storability ofphotographic material has been required to be overcome.

The present invention is concerned with a direct positivelight-sensitive silver halide photographic material incorporated with(1) a fogging agent comprising a polyamine of the below-mentionedgeneral formula (I) in combination with a salt of a metal moreelectropositive than silver, and (2) a compound of the below-mentionedgeneral formula (II).

General formula (I):

wherein m is 0 or an integer of 1 to 8; R is a hydrogen atom, or analkyl group having up to 17 carbon atoms or any aryl group; and M is acation.

We have found that the above-mentioned photographic material is not onlyexcellent in photographic properties but also can overcome thedisadvantages of conventional photographic materials of this kind, ashaving such advantages that it is excellent in stability and thus isextremely less in variation in photographic properties even when storedover a long period of time, and that it can be prepared with ease.

The polyamine of the general formula (I) and the salt of a metal whichis more electropositive than silver are preferably added at a step priorto completion of second ripening of silver halide emulsion. Generally,the polyamine is added in an amount of 1 to 200 mg., preferably 10 tomg., per mole of the silver halide, and the salt of a metal moreelectropositive than silver is added in an amount of 0.1 to 200 mg.,preferably 1 to 100 mg, per mole of the silver halide, whereby thesilver halide emulsion can be properly fogged. The thus obtained fog andother photographic properties of the emulsion can be maintained quitestably over a long period of time when a compound of the aforesaidgeneral for mula (II) is incorporated into the emulsion in a proportionwithin the range from 0.01 to 30 g; per mole of the silver halide, orinto another emulsion layer so that the amount of the compound in saidlayer comes within the said range, before the emulsion is coated, ifnecessary through a sub layer, on a suitable support such as, forexample, paper, glass, cellulose acetate, or a polyester, polyamide,polystyrene, polycarbonate or the like synthetic resin film.

Typical examples of the compounds used in the present invention are asmentioned below.

Examples of the polyamine of the general formula (I):

(1) Diethylenetriamine (2) Triethylenetetramine (3)Tetraethylenepentamine (4) Pentaethylenehexamine (5)Hexaethyleneheptamine (6) Tripropylenetetramine (7) Dibutylenetriarnine(8) Spermine (9') Spermidine (10) N- (4-Aminobutyl) cadaverine Examplesof the salt of a metal more electropositive than silver:

Gold compounds such as gold hydroxide, chloroauric acid and sodiumchloroaurate.

Palladium compounds such as palladous potassium chloride and palladousammonium chloride.

Platinum compounds such as potassium chloroplatinate and ammoniumchloroplatinate.

Examples of the compound of the general formula (II):

(11) HOCH2-S OsNa (12) HOCHS OsNa aHn (13) HO-CHS OaNa 14) HO-CH-S OaNa(15) HO-CH-S OaNa (16) HOCHS OaNa no w (17) H0(CHz)2-S 03K 18)HO-(CH2)3S OaNa (19) HO-CH-S OaNa 20) HO-OHS OaNa S ;|Na

(21) H0CHS OaNa (22) HO-(OHzh-S OaNHa (23) HO-(CHDr-S 03K The aforesaidpolyamine and salt of a metal more electropositive than silver which areused in the present invention are individually known as a fogging agent.The compounds of the general formula (II) can be synthesized, forexample, in such a manner as described in the synthesis examples setforth below.

Synthesis Example 1 Synthesis of the exemplified compound (12): Asolution of 10.4 g. of acidic sodium sulfite in ml. of water wasincorporated with 11.4 g. of n-hexylaldehyde, and then shaken at roomtemperature together with 60 ml. of alcohol, and the resulting mixturewas allowed to stand overnight. Thereafter, the mixture was heated underreflux 4 hours over a water bath, and the resulting pale yellowtransparent reaction liquid was concentrated under reduced pressure toform white crystals. The thus formed crystals were dissolved in awater-methanol mixture and then precipitated by addition of ether.Subsequently, the precipitated crystals were recovered by filtration andthen dried under reduced pressure to obtain 9.5 g. of pure whitecrystals, m.p. 300 C. or more.

Synthesis Example 2 Synthesis of the exemplified compound (13): Asolution of 12.0 g. of acidic potassium sulfite in 30 ml. of pure waterwas incorporated with 10.6 g. of benzaldehyde. The resulting mixture wasstrongly shaken for 20 minutes, whereby white crystals precipitated withgeneration of heat. Subsequently, the mixture was allowed to standovernight, and then the crystals were recovered by filtration. Aftersufliciently squeezing, the crystals were washed with 60 ml. of 8%alcohol and then with 100 ml. of petroleum ether, and thereafter driedunder reduced pressure to obtain 15.8 g. of pure white crystals, m.p.300 C. or more.

Other compounds of the general formula (II) can also be synthesizedaccording to the procedures shown in the above-mentioned synthesisexamples.

The silver halide emulsion used in the present invention may be anemulsion prepared according to any of the known methods, and examples ofthe silver halide include silver chlorobromide, silver bromide, silverchloroiodobromide and silver iodobromide. As the protective colloid inthis case, gelatin is used in general. Alternatively, however, otherhydrophilic organic colloids such as, for example, albumen, polyvinylalcohol, etc., may also be used either singly or in the form of amixture or in combination with gelatin.

Further, the above-mentioned emulsion may contain a spectral sensitizersuch as a cyanine or merocyanine dye, a solarization promoter such as aninorganic or organic halide, an organic desensitizer, such aspynakryptol yellow, phenosafranine, etc., displaying a strongdesensitizing action when added to a conventional negative-positive typesilver halide emulsion, and a metal salt such as rhodium chloride. Theemulsion may further contain a film hardener such as formaldehyde, ahalogen-substituted fatty acid, e.g. mucobromic acid, or glyoxal, awetting agent such as saponin or a salt of sulfated or alkylatedpolyethylene glycol ether, stabilizers, couplers and the likephotographic additives.

The present invention is illustrated in more detail below with referenceto examples, but it is needless to say that the modes of practice of theinvention are not limited to the examples.

Example 1 An emulsion was prepared in the manner described below.

*A solution of 0.1 g. of RllCla.3H2O in 100 cc. of a 25% aqueous sodiumchloride solution.

The liquid (II) was added at 50 C. to the liquid (I), and the liquid(III) was further added thereto with stirring. The resulting mixture wasripened at 50 C. for 40 minutes, incorporated with the liquid (IV) andthen allowed to stand for minutes to prepare an emulsion.

The thus prepared emulsion was divided into emulsions (A) and (B), whichwere then individually incorporated with 10 mg. of triethylenetetramine.The emulsion (B) was further incorporated with 6 mg. of chloroauricacid. The emulsions (A) and (B) were individually ripened for 60 minutesand then cold set. After the setting, each emulsion was extruded tonoodle form and then washed with running water for 30 minutes. Theemulsion (B) was further divided into several emulsions, which were thenindividually incorporated with the exemplified compound shown in Table 1and with formalin and saponin, coated on a transparent support and thendried to pre pare samples. On the other hand, the emulsion (A) wasincorporated with formalin and saponin, coated on a transparent supportand then dried to prepare a sample.

Each of the samples prepared in the above manner was exposed to atungsten lamp through an optical wedge for sensitometry, and thensubjected to ordinary development to measure the reversal speed andmaximum density thereof. The development was carried out by use of aD-72 developer of Eastman Kodak Co. The stability test of each samplewas carried out by allowing the sample to stand for 48 hours in anatmosphere kept at 50 C. and

6 tion which had been incorporated with the compounds of the aforesaidgeneral formula (II) were scarcely changed in speed and lowered inmaximum density even when subjected to the degradation test, and hadquite stable and excellent photographic properties.

Example 2 An emulsion was prepared in the manner described below.

Gelatin g 16 Water cc 110 Sodium chloride ..g 4.8

Silver nitrate g 48 Water cc 400 (III) Potassium bromide g 34 Potassiumiodide g 0.64 Rhodium chloride solution -cc-.. 1.2 Ammonia (28%) cc 40Water cc 370 Glacial acetic acid The liquid (II) was added at 40 C. tothe liquid (I), and the liquid (III) was further added thereto withstirring. The resulting mixture was ripened at 40 C. for 10 minutes, andthen neutralized to a pH of 6.5 by addition of the liquid (IV) toprepare an emulsion.

The thus prepared emulsion was washed with water, incorporated with 12g. of gelatin and then ripened at 50 C. for 10 minutes. Subsequently,the emulsion was divided into several emulsions, which were thenindividually incorporated with each of the exemplified compounds (5),(6), (7) and (8) in such amounts as shown in Table 2.

Each of the above-mentioned emulsions Was incorporated with a compoundof the aforesaid general formula (II) in such amount as shown in Table 2and then with formalin and saponin, coated on a transparent support RH.The results Obtained were as set forth 1n and drled to P p Samples EachSample was exposed Table l. to a tungsten lamp through an optical wedgefor sen- TABLE 1 After incubation at Immediately after 50 C. and 80% RHpreparation for 48 hours Amount of compound Reversal Reversalincorpospeed speed Exemplified rated (mgJ (relative Maximum (relativeMaximum Emulsion compound mole Ag) value) density value) density AControl (I) 0.05 0.04

Control (II) 4. 13 55 4. 09

As is clear from Table 1, no fog was obtained at all whentriethylenetetramine was used singly [Control I)], whereas sufficientfog was obtained when it was used in combination with chloroauric acid[Control (II)]. However, the control (II) showed a markeddesensitization when subjected to the stability test. In consitometry,and then subjected to ordinary development to 70 measure the reversalspeed and maximum density theretrast thereto, the samples according tothe present inven- 75 RH. The results obtained were as set forth inTable 2.

TABLE 2 After incubation at Immediately after 50 C. and 80% RHpreparation for 48 hours Com- Reversal Reversal Compound of pound speedspeed the formula Amount Amount the for- Amount (relative Maximum(relative Maximum (mg.) Gold compound (mg.) mula (II) (mg.) value)density value) density 5 Chloroaurie acid- 10 100 4. 03 48 3. 09 10 Goldhydroxide..- 98 4. 25 39 4.17 35 Sodium chloro- 7 93 4. 31 35 4. 25

aurate. 20 Chloroaurle acld 6 101 4. 02 51 4. do (11) 350 105 4.05 1034. 03 10 Gold hydroxide-.- 3 800 102 4.03 99 4. 06 35 Sodium ch10ro- 7(12) 450 100 4.03 98 4. 01

aura e. Chloroauric acid.. 6 (20) 1, 000 110 4. 00 105 4. 03 5 do 6 (12)200 107 4.04 103 v 4.04

As is clear from Table 2, the samples according to the present inventionhad quite stable and excellent photographic properties.

What we claim is:

1. A direct positive light-sensitive silver halide photographic emulsionwhich contains silver halide grains fogged with from 1 to 200 mg. permole of silver halide of a polyamine of the formula (1),

wherein n is an integer of 1 to 5, and Y is an alkylene group having 2to 4 carbon atoms, provided that 2 or more Ys present in one moleculemay be different alkylene groups and from 0.1 to 200 mg. per mole ofsilver halide of a salt of a metal more electropositive than silver, anda stabilizing amount from 0.1 to 30 g. per mole of silver halide of acompound of the formula (II),

wherein m is 0 or an integer of 1 to 8, R is a hydrogen atom, or analkyl group having up to 17 carbon atoms, or an aryl group selected fromthe group consisting of a phenyl group and a napthyl which may besubstituted with hydroxyl, carboxyl or sulfo groups and M is a cation.

2. A direct positive light-sensitive silver halide photographic emulsionas claimed in claim 1, wherein said polyamine is a member selected fromthe group consisting of diethylenetriamine, triethylenetetramine,tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine,tripropylenetetramine, dibutylenetriamine, spermine, spermidine andN-(4-aminobutyl)cadaverine.

3. A direct positive light-sensitive silver halide photographic emulsionas claimed in claim 1, wherein said metal is gold, palladium orplatinum.

4. A direct positive light-sensitive silver halide photographic emulsionas claimed in claim 1, wherein the compound of the general formula (II)is a compound having any one of the following chemical structures:

HO(CH2)2S OaK, HO-(CHzh-S OaNa, HO-CH-S OaNa HO--CHS OaNa, HOCH--S OaNa,HO(CH2)4--S OaNHg References Cited UNITED STATES PATENTS 3/1970Illingsworth 96108 7/1971 Haga et a1. 96109 RONALD H. SMITH, PrimaryExaminer W. H. LOVIE, JR., Assistant Examiner US. Cl. X.R. 96109

